# AD 60-02-04: Mach Trim Warning Lights

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 707-100 Long Body, 707-100B Long Body, 707-100B Short Body, 707-200, 707-300 Series, 707-300B Series, 707-300C Series and 707-400 Series
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 6 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6E0F6099D4AA76A98625698B0067CAE4.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/60-02-04

## The airworthiness directive

60-02-04 BOEING: Amdt. 86 Part 507 Federal Register January 21, 1960. Applies to the following Model 707 Series aircraft only: Serial Numbers 17586 through 17591, 17609 through 17612, 17628 through 17652, 17658 through 17672, 17691, 17696 through 17702, 17925 through 17927.

To increase the capabilities and reliability of the Mach trim warning lights and the Mach warning and fire warning bell systems the following modification(s) shall be accomplished as indicated:

Unless already completed, the following shall be accomplished by April 30, 1960.

  (a) Remove Mach and fire warning bell support bracket, Boeing P/N 69-1640, from below flight engineer's table and rework to accept redesigned warning bell assembly Boeing P/N 69-50013 or equivalent. Install reworked bracket and redesigned components as shown in Boeing Drawing 65-2801. (Boeing Service Bulletin No. 444 pertains to this same subject.)

  (b) Install two diodes, Boeing assembly 69-43070-6, in the Mach trim systemresistor box and revise the indicating light circuitry such that this light will indicate when the system is not turned on as well as indicating Mach trim system malfunctions. (Boeing Service Bulletin No. 474 (R-1) describes a satisfactory modification.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A21](https://openairdocs.org/tcds/4A21): The Boeing Company; names 4 of 4 models: 707-100B Short Body, 707-200, 707-100 Long Body, 707-100B Long Body
- [TCDS 4A26](https://openairdocs.org/tcds/4A26): The Boeing Company; names 4 of 4 models: 707-300B Series, 707-400 Series, 707-300 Series, 707-300C Series

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 6 (6 by airframe model, 0 by engine model)
- Makers: Boeing 6

Models with the most aircraft:

- [Boeing 707-338C](https://openairdocs.org/model/boeing-707-338c): 2 aircraft (airframe model)
- [Boeing 707-368C](https://openairdocs.org/model/boeing-707-368c): 1 aircraft (airframe model)
- [Boeing 707-321B](https://openairdocs.org/model/boeing-707-321b): 1 aircraft (airframe model)
- [Boeing 707-323B](https://openairdocs.org/model/boeing-707-323b): 1 aircraft (airframe model)
- [Boeing 707-351B](https://openairdocs.org/model/boeing-707-351b): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/60-02-04/models.md
Every aircraft: https://openairdocs.org/ad/60-02-04/aircraft.md

Its text cites no advisory circulars or STCs.

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